The high surface area of porous media enhances its efficacy for evaporative cooling,however,the evaporation of pure substances often encounters issues including local overheating and unstable heat transfer.To address ...The high surface area of porous media enhances its efficacy for evaporative cooling,however,the evaporation of pure substances often encounters issues including local overheating and unstable heat transfer.To address these challenges,a volume of fluid(VOF)model integrated with a species transport model was developed to predict the evaporation processes of ternary mixtures(water,glycerol,and 1,2-propylene glycol)in porous ceramics in this study.It reveals that the synergistic effects of thermal conduction and convective heat transfer significantly influence the mixtures evaporation,causing the fluctuations in evaporation rates.The obtained result shows a significant increase in water evaporation rates with decreasing the microcolumn size.At a pore size of 30μm and a porosity of 30%,an optimal balance between capillary forces and flow resistance yields a peak water release rate of 96.0%.Furthermore,decreasing the glycerol content from 70%to 60%enhances water release by 10.6%.The findings in this work propose the approaches to optimize evaporative cooling technologies by controlling the evaporation of mixtures in porous media.展开更多
A solid ternary mixture consisting of NaF, silicon and one of the metal oxides such as Al2O3, MgO, CaO, SrO, BaO was prepared and used as a defluorinated reagent for CF4 decomposition. The results show that the initia...A solid ternary mixture consisting of NaF, silicon and one of the metal oxides such as Al2O3, MgO, CaO, SrO, BaO was prepared and used as a defluorinated reagent for CF4 decomposition. The results show that the initial conversion of CF4 reached 100% over NaF-Si-MgO and NaF-Si-CaO at 850°C, and the reagent with NaF/Si/MgO molar ratio of 33/34/33 exhibited a high reactivity with a full conversion of CF4 lasting for 57 min. The plausible paths of CF4 decomposition over NaF-Si-Al2O3, NaF-Si-MgO, NaF-Si-CaO, NaF-Si-SrO and NaF-Si-BaO are proposed.展开更多
A solid ternary mixture consisting of NaF,silicon and one metal oxide such as La2O3,CeO2,Pr6O11,Nd2O3,and Y2O3 was prepared and usedas de-fluorinated reagent for CF4 decomposition.The results show that 90% conversion ...A solid ternary mixture consisting of NaF,silicon and one metal oxide such as La2O3,CeO2,Pr6O11,Nd2O3,and Y2O3 was prepared and usedas de-fluorinated reagent for CF4 decomposition.The results show that 90% conversion of CF4 can be reached initially over NaF-Si-La2O3,NaF-Si-CeO2,NaF-Si-Nd2O3,and NaF-Si-Y2O3 at 850 C.The fresh and used reagents were characterized using XRD and XPS techniques.It was found that the active components of NaF and metal oxides in NaF-Si-CeO2,NaF-Si-Pr6O11,NaF-Si-Nd2O3,and NaF-Si-Y2O3 weretransformed into inert phases of mixed metal fluorides and silicates,respectively,resulting in an ineffective utilization of these de-fluorinatedreagents,whereas no inert phases from NaF and La2O3 can be observed in the used NaF-Si-La2O3,indicating the NaF-Si-La2O3 reagent couldbe utilized more efficiently than the other reagents in CF4 decomposition.展开更多
The objective of present study was to produce poultry feed with a best quality using ternary mixture of industrial wastes: fish industry waste, sugar industry waste (molasses) and yeast waste after 15 d biotransfor...The objective of present study was to produce poultry feed with a best quality using ternary mixture of industrial wastes: fish industry waste, sugar industry waste (molasses) and yeast waste after 15 d biotransformation using response surface methodology to design and analyze the experiment data. Changes in the nutritional quality and biochemical properties viz., pH, dry matter, conductivity, total organic carbon, total nitrogen, phosphorus, trimethylamine, protein, fat, carbohydrate, histamine, aflatoxins and minerals were evaluated during a biotransformation period of 15 d. The experimental findings revealed that the formulation including 50% of fish waste, 12.5% of molasses and 37.50% of yeast waste were found to be best quality poultry waste. It was characterized as odorless, with a stable pH, rich in protein, fat and carbohydrate as well as no alterations of bacteria and absence aflatoxins from the fifth day on ward. The nutritional value of the developed poultry fees was studied on a population of broiler chickens by incorporating with barley flour and eggshell. The product possesses a better nutritional quality comparable to commercially feed.展开更多
We use a Monte Carlo method to study the phase and interracial behaviors of A-b-B diblocks in a blend of homopolymers, A and B, which are confined between two asymmetric hard and impenetrable walls. Our results show t...We use a Monte Carlo method to study the phase and interracial behaviors of A-b-B diblocks in a blend of homopolymers, A and B, which are confined between two asymmetric hard and impenetrable walls. Our results show that, when the interaction strength is weak, the block copolymers are uniformly distributed in the ternary mixtures under considered concentrations. Under strong interaction strength, distribution region of the block copolymers changes from a single smooth interface to a curved interface or multi-layer interface in the ternary mixtures. Furthermore, our findings show that with increasing volume fraction of A-b-B diblock copolymer (φc), copolymer profiles broaden while φc ≥ 0.4, a lamellar phase is formed and by further increasing φc, more thinner layers are observed. Moreover, the results show that, with the increase of φc, the phase interface first gradually transforms from plane to a curved surface rather than micelle or lamellar phase while with the increase of the interaction between A and B segments (CAB), the copolymer chains not only get stretched in the direction perpendicular to the interface, but also are oriented. The simulations also reveal that the difference between symmetric and asymmetric copolymers is negligible in statistics if the lengths of two blocks are comparable.展开更多
The segregation behavior of a mixture of silica-coated titanium dioxide(TiO2)particles of three different sizes in a pseudo two-dimensional fluidized bed was studied experimentally by the freeze-sieving method and num...The segregation behavior of a mixture of silica-coated titanium dioxide(TiO2)particles of three different sizes in a pseudo two-dimensional fluidized bed was studied experimentally by the freeze-sieving method and numerically by the multi-fluid model(MFM).Three-dimensional computational fluid dynamics(CFD)simulations were carried out to evaluate the effects of the solid wall boundary conditions on particle segregation in terms of specularity and particle-wall restitution coefficients.The quantitative indexes of segregation tendency and segregation degree were used to determine the axial segregation of the mixture in triangular coordinates.The simulation results revealed that the axial segregation increased with the specularity coefficient,whereas the particle-wall restitution coefficient had a minor effect on axial segregation.Comparison of the simulation results with experimental data showed that the appropriate value of the specularity coefficient used in the CFD model depended on superficial gas velocity.The study of the effects of superficial gas velocity on segregation behavior demonstrated that the greatest segregation was obtained at minimum fluidization velocity and the segregation decreased as the gas velocity gradually increased.展开更多
Hydrodynamic characteristics of fluidization in a conical or tapered bed differ from those in a columnar bed because the superficial velocity in the bed varies in the axial direction. Fixed and fluidized regions could...Hydrodynamic characteristics of fluidization in a conical or tapered bed differ from those in a columnar bed because the superficial velocity in the bed varies in the axial direction. Fixed and fluidized regions could coexist and sharp variations in pressure drop could occur, thereby giving rise to a noticeable pressure drop-flow rate hysteresis loop under incipient fluidization conditions. To explore these unique properties, several experiments were carried out using homogeneous, well-mixed, ternary mixtures with three dif- ferent particle sizes at varying composition in gas-solid conical fluidized beds with varying cone angles. The hydrodynamic characteristics determined include the minimum fluidization velocity, bed fluctuation, and bed expansion ratios. The dependence of these quantities on average particle diameter, mass fraction of the fines in the mixture, initial static bed height, and cone angle is discussed. Based on dimensional analysis and factorial design, correlations are developed using the system parameters, i.e. geometry of the bed (cone angle), particle diameter, initial static bed height, density of the solid, and superficial velocity of the fluidizing medium. Experimental values of minimum fluidization velocity, bed fluctuation, and bed expansion ratios were found to agree well with the developed correlations.展开更多
This paper presents a simple but informative mathematical model to describe the mixing of three dissimilar components of particulate solids that have the tendency to segregate within one another. A nonlinear Markov ch...This paper presents a simple but informative mathematical model to describe the mixing of three dissimilar components of particulate solids that have the tendency to segregate within one another. A nonlinear Markov chain model is proposed to describe the process. At each time step, the exchange of particulate solids between the cells of the chain is divided into two virtual stages. The first is pure stochastic mixing accompanied by downward segregation. Upon the completion of this stage, some of the cells appear to be overfilled with the mixture, while others appear to have a void space. The second stage is related to upward segregation. Components from the overfilled cells fill the upper cells (those with the void space) according to the proposed algorithm. The degree of non-homogeneity in the mixture (the standard deviation) is calculated at each time step, which allows the mixing kinetics to be described. The optimum mixing time is found to provide the maximum homogeneity in the ternary mixture. However, this “common” time differs from the optimum mixing times for individual components. The model is verified using a lab-scale vibration vessel, and a reasonable correlation between the calculated and experimental data is obtained展开更多
In the industrial treatment of waste volatile organic compound(VOC)streams by membrane technology,a third impurity,generally,water vapor,coexists in the mixture of VOC and nitrogen or air,and can affect membrane perfo...In the industrial treatment of waste volatile organic compound(VOC)streams by membrane technology,a third impurity,generally,water vapor,coexists in the mixture of VOC and nitrogen or air,and can affect membrane performance and the design of the industrial process.This study focused on the investigation of the effect of water vapor on the separation performance of the separation of VOC/water/nitrogen mixtures by a polydimethylsiloxane(PDMS)membrane.Three types of VOCs:water-miscible ethanol,water-semi-miscible butanol,and water-immiscible cyclohexane,were selected for the study.Different operating parameters including,concentration of the feed VOC,feed temperature,and concentration of the feed water were compared for the separation of binary and ternary VOC/nitrogen mixtures.The interaction between the VOC and water was analyzed to explain the transportation mechanism after analyzing the difference in the membrane performance for the separation of binary and ternary mixtures.The results indicated that the interaction between the VOC(or nitrogen)and water is the key factor affecting membrane performance.Water can promote the permeation of hydrophilic VOC but prevent hydrophobic VOC through the membrane for the separation of ternary VOC/water/nitrogen mixtures.These results will provide fundamental insights for the design of the recovery application process for industrial membrane-based VOCs,and also guidance for the investigation of the separation mechanism in vapor permeation.展开更多
In this paper, the mixture of dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate was separated by middle-vessel batch distillation with feeding in middle-vessel and process control characteristics were r...In this paper, the mixture of dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate was separated by middle-vessel batch distillation with feeding in middle-vessel and process control characteristics were researched. The steady state simulation results in Aspen Plus were exported to Aspen Dynamics. Then control effect of liquid level control with HighSelector, composition control(structure1, structure2) and temperature control(proportional action, proportional integration action) were proposed. Composition control structure 2 and temperature control with PI action were investigated to achieve a good control effect.展开更多
Critical temperature (Tc) and critical pressure (pc) of the ternary mixture of ethylene+benzene+ethylbenzene (the mole ratio of ethylbenzene to benzene was fixed at 0.95:0.05) were measured by using a high=pressure vi...Critical temperature (Tc) and critical pressure (pc) of the ternary mixture of ethylene+benzene+ethylbenzene (the mole ratio of ethylbenzene to benzene was fixed at 0.95:0.05) were measured by using a high=pressure view cell with direct visual observation.The interaction coefficients obtained from the critical properties of the relevant binary systems were used to predict the critical properties (Tc,pc) of the ternary mixture.The agreement between the prediction and experiments is satisfactory.展开更多
Is it possible to improve CO_(2)solubility in potassium carbonate(K_(2)CO_(3))-based transition temperature mixtures(TTMs)?To assess this possibility,a ternary transition-temperature mixture(TTTM)was prepared by using...Is it possible to improve CO_(2)solubility in potassium carbonate(K_(2)CO_(3))-based transition temperature mixtures(TTMs)?To assess this possibility,a ternary transition-temperature mixture(TTTM)was prepared by using a hindered amine,2-amino-2-methyl-1,3-propanediol(AMPD).Fourier transform infrared spectroscopy(FT-IR)was employed to detect the functional groups including hydroxyl,amine,carbonate ion,and aliphatic functional groups in the prepared solvents.From thermogravimetric analysis(TGA),it was found that the addition of AMPD to the binary mixture can increase the thermal stability of TTTM.The viscosity findings showed that TTTM has a higher viscosity than TTM while their difference was decreased by increasing temperature.In addition,Eyring’s absolute rate theory was used to compute the activation parameters(∆G^(*),∆H^(*),and ∆S^(*)).The CO_(2)solubility in liquids was measured at a temperature of 303.15 K and pressures up to 1.8 MPa.The results disclosed that the CO_(2)solubility of TTTM was improved by the addition of AMPD.At the pressure of about 1.8 MPa,the CO_(2)mole fractions of TTM and TTTM were 0.1697 and 0.2022,respectively.To confirm the experimental data,density functional theory(DFT)was employed.From the DFT analysis,it was found that the TTTM+CO_(2)system has higher interaction energy(|∆E|)than the TTM+CO_(2)system indicating the higher CO_(2)affinity of the former system.This study might help scientists to better understand and to improve CO_(2)solubility in these types of solvents by choosing a suitable amine as HBD and finding the best combination of HBA and HBD.展开更多
The lauric-myristic-palmitic acid( LA-MA-PA) ternary eutectic mixtures/expanded graphite( EG) composite phase change materials( PCMs) were prepared by absorbing LA-MA-PA into the porous network of EG. The optimum rati...The lauric-myristic-palmitic acid( LA-MA-PA) ternary eutectic mixtures/expanded graphite( EG) composite phase change materials( PCMs) were prepared by absorbing LA-MA-PA into the porous network of EG. The optimum ratio of ternary eutectic mixtures to EG was determined to be 93∶7 without liquid LA-MA-PA leakage from the composite PCMs. In order to make the structure more stable, the composite PCMs were encapsulated by surface treatment agent to prepare LA-MA-PA/EG encapsulating form-stable PCMs which were characterized by scanning electron microscope( SEM),Fourier transformation infrared spectroscope( FT-IR),differential scanning calorimetry( DSC) and thermal treatment. The results showed there was no chemical reaction between surface treatment agent and LA-MA-PA,and the samples were compactly encapsulated which left almost no imprint on the filter paper after thermal treatment. The phase change temperature and latent heat of LA-MA-PA/EG encapsulating form-stable PCMs were tested to be29. 32 ℃ and 96. 20 J/g,respectively. Additionally,the heat transfer efficiency of heat storage was improved by the addition of EG.展开更多
Using a high-viscosity Newtonian fluid, glycerol, an experimental investigation was carried out to evaluate the stable spouting regime in conical spouted beds using four particle mixtures: a reference (monoparticles...Using a high-viscosity Newtonian fluid, glycerol, an experimental investigation was carried out to evaluate the stable spouting regime in conical spouted beds using four particle mixtures: a reference (monoparticles), a binary mixture, two ternary mixtures with flat and Gaussian distributions respectively. The mixtures were selected for particle diameters (dp) ranging from 1.09 to 4.98 mm and particle diameter ratios (dpL/dps) ranging from 1.98 to 4.0. Experimental data show that pressure fluctuation signals of the bed, as indicated by changes in their standard deviations, provide suitable information to identify the range of operational conditions for stable spouting. However, the analysis of skewness of curves of pressure fluctuation as a function of air velocity appears not sufficient to identify a particular flow regime. For glycerol in the spouting regime, the standard deviation is noted to increase with increasing glycerol concentration due to the growth of interparticle forces. The implications of these research findings on the drying of suspensions in conical spouted beds using glass bead mixtures are also discussed.展开更多
The significance of gas compressibility factor in petroleum engineering encourages the researchers to employ the most accurate and precise methods for estimation of this factor.Commonly,empirical correlations due to t...The significance of gas compressibility factor in petroleum engineering encourages the researchers to employ the most accurate and precise methods for estimation of this factor.Commonly,empirical correlations due to their simplicity have been referred more than other approaches for prediction of Z-factor.There is no clear and reliable report to address an appropriate combination of correlation and mixing rule for each type of gas.In the present study,combination of several empirical correlations and mixing rules is examined and a decision tree is constructed to suggest best combination for each gas system.For this reason,2329 experimental data were used for analysis.According to the results,LelandeMueller mixing rule/Sanjari and Lay correlation is the best combination for sour and natural gas.Also,Van NesseAbbot mixing rule/HalleYarborough correlation,StewarteBurkhardteVoo mixing rule/Heidarian correlation and SattereCampbell mixing rule/Papay correlation are the most appropriate combination for gas condensate,binary and ternary mixtures respectively.For binary mixtures,a robust and novel empirical correlation was developed based on Kay mixing rule to estimate Z-factor.The results employed how good the new correlation is in agreement with the experimental data with significant R-squared 0.9843.展开更多
文摘The high surface area of porous media enhances its efficacy for evaporative cooling,however,the evaporation of pure substances often encounters issues including local overheating and unstable heat transfer.To address these challenges,a volume of fluid(VOF)model integrated with a species transport model was developed to predict the evaporation processes of ternary mixtures(water,glycerol,and 1,2-propylene glycol)in porous ceramics in this study.It reveals that the synergistic effects of thermal conduction and convective heat transfer significantly influence the mixtures evaporation,causing the fluctuations in evaporation rates.The obtained result shows a significant increase in water evaporation rates with decreasing the microcolumn size.At a pore size of 30μm and a porosity of 30%,an optimal balance between capillary forces and flow resistance yields a peak water release rate of 96.0%.Furthermore,decreasing the glycerol content from 70%to 60%enhances water release by 10.6%.The findings in this work propose the approaches to optimize evaporative cooling technologies by controlling the evaporation of mixtures in porous media.
基金financially supported by the National Natural Science Foundation of China(No.20976149)
文摘A solid ternary mixture consisting of NaF, silicon and one of the metal oxides such as Al2O3, MgO, CaO, SrO, BaO was prepared and used as a defluorinated reagent for CF4 decomposition. The results show that the initial conversion of CF4 reached 100% over NaF-Si-MgO and NaF-Si-CaO at 850°C, and the reagent with NaF/Si/MgO molar ratio of 33/34/33 exhibited a high reactivity with a full conversion of CF4 lasting for 57 min. The plausible paths of CF4 decomposition over NaF-Si-Al2O3, NaF-Si-MgO, NaF-Si-CaO, NaF-Si-SrO and NaF-Si-BaO are proposed.
基金supported by the National Natural Science Foundation of China (No. 20976149)
文摘A solid ternary mixture consisting of NaF,silicon and one metal oxide such as La2O3,CeO2,Pr6O11,Nd2O3,and Y2O3 was prepared and usedas de-fluorinated reagent for CF4 decomposition.The results show that 90% conversion of CF4 can be reached initially over NaF-Si-La2O3,NaF-Si-CeO2,NaF-Si-Nd2O3,and NaF-Si-Y2O3 at 850 C.The fresh and used reagents were characterized using XRD and XPS techniques.It was found that the active components of NaF and metal oxides in NaF-Si-CeO2,NaF-Si-Pr6O11,NaF-Si-Nd2O3,and NaF-Si-Y2O3 weretransformed into inert phases of mixed metal fluorides and silicates,respectively,resulting in an ineffective utilization of these de-fluorinatedreagents,whereas no inert phases from NaF and La2O3 can be observed in the used NaF-Si-La2O3,indicating the NaF-Si-La2O3 reagent couldbe utilized more efficiently than the other reagents in CF4 decomposition.
文摘The objective of present study was to produce poultry feed with a best quality using ternary mixture of industrial wastes: fish industry waste, sugar industry waste (molasses) and yeast waste after 15 d biotransformation using response surface methodology to design and analyze the experiment data. Changes in the nutritional quality and biochemical properties viz., pH, dry matter, conductivity, total organic carbon, total nitrogen, phosphorus, trimethylamine, protein, fat, carbohydrate, histamine, aflatoxins and minerals were evaluated during a biotransformation period of 15 d. The experimental findings revealed that the formulation including 50% of fish waste, 12.5% of molasses and 37.50% of yeast waste were found to be best quality poultry waste. It was characterized as odorless, with a stable pH, rich in protein, fat and carbohydrate as well as no alterations of bacteria and absence aflatoxins from the fifth day on ward. The nutritional value of the developed poultry fees was studied on a population of broiler chickens by incorporating with barley flour and eggshell. The product possesses a better nutritional quality comparable to commercially feed.
基金supported by the National Natural Science Foundation of China(Nos.21304097,21334007and 21674113)
文摘We use a Monte Carlo method to study the phase and interracial behaviors of A-b-B diblocks in a blend of homopolymers, A and B, which are confined between two asymmetric hard and impenetrable walls. Our results show that, when the interaction strength is weak, the block copolymers are uniformly distributed in the ternary mixtures under considered concentrations. Under strong interaction strength, distribution region of the block copolymers changes from a single smooth interface to a curved interface or multi-layer interface in the ternary mixtures. Furthermore, our findings show that with increasing volume fraction of A-b-B diblock copolymer (φc), copolymer profiles broaden while φc ≥ 0.4, a lamellar phase is formed and by further increasing φc, more thinner layers are observed. Moreover, the results show that, with the increase of φc, the phase interface first gradually transforms from plane to a curved surface rather than micelle or lamellar phase while with the increase of the interaction between A and B segments (CAB), the copolymer chains not only get stretched in the direction perpendicular to the interface, but also are oriented. The simulations also reveal that the difference between symmetric and asymmetric copolymers is negligible in statistics if the lengths of two blocks are comparable.
文摘The segregation behavior of a mixture of silica-coated titanium dioxide(TiO2)particles of three different sizes in a pseudo two-dimensional fluidized bed was studied experimentally by the freeze-sieving method and numerically by the multi-fluid model(MFM).Three-dimensional computational fluid dynamics(CFD)simulations were carried out to evaluate the effects of the solid wall boundary conditions on particle segregation in terms of specularity and particle-wall restitution coefficients.The quantitative indexes of segregation tendency and segregation degree were used to determine the axial segregation of the mixture in triangular coordinates.The simulation results revealed that the axial segregation increased with the specularity coefficient,whereas the particle-wall restitution coefficient had a minor effect on axial segregation.Comparison of the simulation results with experimental data showed that the appropriate value of the specularity coefficient used in the CFD model depended on superficial gas velocity.The study of the effects of superficial gas velocity on segregation behavior demonstrated that the greatest segregation was obtained at minimum fluidization velocity and the segregation decreased as the gas velocity gradually increased.
文摘Hydrodynamic characteristics of fluidization in a conical or tapered bed differ from those in a columnar bed because the superficial velocity in the bed varies in the axial direction. Fixed and fluidized regions could coexist and sharp variations in pressure drop could occur, thereby giving rise to a noticeable pressure drop-flow rate hysteresis loop under incipient fluidization conditions. To explore these unique properties, several experiments were carried out using homogeneous, well-mixed, ternary mixtures with three dif- ferent particle sizes at varying composition in gas-solid conical fluidized beds with varying cone angles. The hydrodynamic characteristics determined include the minimum fluidization velocity, bed fluctuation, and bed expansion ratios. The dependence of these quantities on average particle diameter, mass fraction of the fines in the mixture, initial static bed height, and cone angle is discussed. Based on dimensional analysis and factorial design, correlations are developed using the system parameters, i.e. geometry of the bed (cone angle), particle diameter, initial static bed height, density of the solid, and superficial velocity of the fluidizing medium. Experimental values of minimum fluidization velocity, bed fluctuation, and bed expansion ratios were found to agree well with the developed correlations.
文摘This paper presents a simple but informative mathematical model to describe the mixing of three dissimilar components of particulate solids that have the tendency to segregate within one another. A nonlinear Markov chain model is proposed to describe the process. At each time step, the exchange of particulate solids between the cells of the chain is divided into two virtual stages. The first is pure stochastic mixing accompanied by downward segregation. Upon the completion of this stage, some of the cells appear to be overfilled with the mixture, while others appear to have a void space. The second stage is related to upward segregation. Components from the overfilled cells fill the upper cells (those with the void space) according to the proposed algorithm. The degree of non-homogeneity in the mixture (the standard deviation) is calculated at each time step, which allows the mixing kinetics to be described. The optimum mixing time is found to provide the maximum homogeneity in the ternary mixture. However, this “common” time differs from the optimum mixing times for individual components. The model is verified using a lab-scale vibration vessel, and a reasonable correlation between the calculated and experimental data is obtained
基金the National Key Research and Development Program of China(2021YFC2101201,2022YFB3805203)the National Natural Science Foundation of China(22278208)。
文摘In the industrial treatment of waste volatile organic compound(VOC)streams by membrane technology,a third impurity,generally,water vapor,coexists in the mixture of VOC and nitrogen or air,and can affect membrane performance and the design of the industrial process.This study focused on the investigation of the effect of water vapor on the separation performance of the separation of VOC/water/nitrogen mixtures by a polydimethylsiloxane(PDMS)membrane.Three types of VOCs:water-miscible ethanol,water-semi-miscible butanol,and water-immiscible cyclohexane,were selected for the study.Different operating parameters including,concentration of the feed VOC,feed temperature,and concentration of the feed water were compared for the separation of binary and ternary VOC/nitrogen mixtures.The interaction between the VOC and water was analyzed to explain the transportation mechanism after analyzing the difference in the membrane performance for the separation of binary and ternary mixtures.The results indicated that the interaction between the VOC(or nitrogen)and water is the key factor affecting membrane performance.Water can promote the permeation of hydrophilic VOC but prevent hydrophobic VOC through the membrane for the separation of ternary VOC/water/nitrogen mixtures.These results will provide fundamental insights for the design of the recovery application process for industrial membrane-based VOCs,and also guidance for the investigation of the separation mechanism in vapor permeation.
基金Supported by the National Natural Science Foundation of China(21676299,21476261,21506255)
文摘In this paper, the mixture of dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate was separated by middle-vessel batch distillation with feeding in middle-vessel and process control characteristics were researched. The steady state simulation results in Aspen Plus were exported to Aspen Dynamics. Then control effect of liquid level control with HighSelector, composition control(structure1, structure2) and temperature control(proportional action, proportional integration action) were proposed. Composition control structure 2 and temperature control with PI action were investigated to achieve a good control effect.
基金Supported by the National Natural Science Foundation of China(Project No. 20025618).
文摘Critical temperature (Tc) and critical pressure (pc) of the ternary mixture of ethylene+benzene+ethylbenzene (the mole ratio of ethylbenzene to benzene was fixed at 0.95:0.05) were measured by using a high=pressure view cell with direct visual observation.The interaction coefficients obtained from the critical properties of the relevant binary systems were used to predict the critical properties (Tc,pc) of the ternary mixture.The agreement between the prediction and experiments is satisfactory.
基金support of National Key Research and Development Program of China(Grant No.2019YFC1904602)the Key SCI-Tech Innovation 2025 Program of Ningbo,China(Grant No.2018B10025).
文摘Is it possible to improve CO_(2)solubility in potassium carbonate(K_(2)CO_(3))-based transition temperature mixtures(TTMs)?To assess this possibility,a ternary transition-temperature mixture(TTTM)was prepared by using a hindered amine,2-amino-2-methyl-1,3-propanediol(AMPD).Fourier transform infrared spectroscopy(FT-IR)was employed to detect the functional groups including hydroxyl,amine,carbonate ion,and aliphatic functional groups in the prepared solvents.From thermogravimetric analysis(TGA),it was found that the addition of AMPD to the binary mixture can increase the thermal stability of TTTM.The viscosity findings showed that TTTM has a higher viscosity than TTM while their difference was decreased by increasing temperature.In addition,Eyring’s absolute rate theory was used to compute the activation parameters(∆G^(*),∆H^(*),and ∆S^(*)).The CO_(2)solubility in liquids was measured at a temperature of 303.15 K and pressures up to 1.8 MPa.The results disclosed that the CO_(2)solubility of TTTM was improved by the addition of AMPD.At the pressure of about 1.8 MPa,the CO_(2)mole fractions of TTM and TTTM were 0.1697 and 0.2022,respectively.To confirm the experimental data,density functional theory(DFT)was employed.From the DFT analysis,it was found that the TTTM+CO_(2)system has higher interaction energy(|∆E|)than the TTM+CO_(2)system indicating the higher CO_(2)affinity of the former system.This study might help scientists to better understand and to improve CO_(2)solubility in these types of solvents by choosing a suitable amine as HBD and finding the best combination of HBA and HBD.
基金National Science&Technology Pillar Program during the Twelfth Five-Year Plan Period,China(No.2014BAL03B04)
文摘The lauric-myristic-palmitic acid( LA-MA-PA) ternary eutectic mixtures/expanded graphite( EG) composite phase change materials( PCMs) were prepared by absorbing LA-MA-PA into the porous network of EG. The optimum ratio of ternary eutectic mixtures to EG was determined to be 93∶7 without liquid LA-MA-PA leakage from the composite PCMs. In order to make the structure more stable, the composite PCMs were encapsulated by surface treatment agent to prepare LA-MA-PA/EG encapsulating form-stable PCMs which were characterized by scanning electron microscope( SEM),Fourier transformation infrared spectroscope( FT-IR),differential scanning calorimetry( DSC) and thermal treatment. The results showed there was no chemical reaction between surface treatment agent and LA-MA-PA,and the samples were compactly encapsulated which left almost no imprint on the filter paper after thermal treatment. The phase change temperature and latent heat of LA-MA-PA/EG encapsulating form-stable PCMs were tested to be29. 32 ℃ and 96. 20 J/g,respectively. Additionally,the heat transfer efficiency of heat storage was improved by the addition of EG.
文摘Using a high-viscosity Newtonian fluid, glycerol, an experimental investigation was carried out to evaluate the stable spouting regime in conical spouted beds using four particle mixtures: a reference (monoparticles), a binary mixture, two ternary mixtures with flat and Gaussian distributions respectively. The mixtures were selected for particle diameters (dp) ranging from 1.09 to 4.98 mm and particle diameter ratios (dpL/dps) ranging from 1.98 to 4.0. Experimental data show that pressure fluctuation signals of the bed, as indicated by changes in their standard deviations, provide suitable information to identify the range of operational conditions for stable spouting. However, the analysis of skewness of curves of pressure fluctuation as a function of air velocity appears not sufficient to identify a particular flow regime. For glycerol in the spouting regime, the standard deviation is noted to increase with increasing glycerol concentration due to the growth of interparticle forces. The implications of these research findings on the drying of suspensions in conical spouted beds using glass bead mixtures are also discussed.
文摘The significance of gas compressibility factor in petroleum engineering encourages the researchers to employ the most accurate and precise methods for estimation of this factor.Commonly,empirical correlations due to their simplicity have been referred more than other approaches for prediction of Z-factor.There is no clear and reliable report to address an appropriate combination of correlation and mixing rule for each type of gas.In the present study,combination of several empirical correlations and mixing rules is examined and a decision tree is constructed to suggest best combination for each gas system.For this reason,2329 experimental data were used for analysis.According to the results,LelandeMueller mixing rule/Sanjari and Lay correlation is the best combination for sour and natural gas.Also,Van NesseAbbot mixing rule/HalleYarborough correlation,StewarteBurkhardteVoo mixing rule/Heidarian correlation and SattereCampbell mixing rule/Papay correlation are the most appropriate combination for gas condensate,binary and ternary mixtures respectively.For binary mixtures,a robust and novel empirical correlation was developed based on Kay mixing rule to estimate Z-factor.The results employed how good the new correlation is in agreement with the experimental data with significant R-squared 0.9843.